Tunable rGO-integrated ZnO/PMMA ternary photoanodes for high-efficiency dye-sensitized solar cells

Photovoltaic measurements showed that J_{sc}, fill factor, and overall power conversion efficiency increased progressively from ZRP-1:1 to ZRP-1:4. ZRP-1:4 achieved the highest performance, displaying superior electron-transport pathways and minimized interfacial losses. Structural characterization confirmed that greater reduced graphene oxide (rGO) content improved crystallinity and reduced defect density. UV–vis absorption spectra showed enhanced visible-light harvesting and a redshift in the optical band gap, while photoluminescence measurements showed pronounced emission quenching, confirming suppressed recombination and more efficient charge extraction.